backup timer. I’d planned for redundancy, at least I thought I had. I can’t believe I forgot to bring a backup for the capacitors.” He frowned. It was almost a fatal oversight. He should have known better, planned better. “I guess I’m older than I thought.”
The ground trembled, an almost imperceptible shift at first, then much harder shaking. The sound of cracking, splintering rock boomed up from the depths of the crevasse. Another tremor hit, a strong sideways motion. Rock fragments fell on them. A cloud of dust formed in the tunnel. They heard a heavy rumble somewhere above them. It sounded like an avalanche.
“That’s a cave-in,” Murray said, coughing in the thick dust. “A big one.”
“How long did it last?” Elizabeth asked. She held a handkerchief over her mouth in the dust. Murray and Booker had dropped to their knees to keep from being knocked down.
“Five seconds,” Atkins said. He’d timed the shaking, the longest since they’d entered the mine.
“Folks, I suggest we switch to plan B and get moving,” Murray said, clearing his throat as the dust settled.
Atkins agreed. The fault’s seismicity was increasing. The pattern closely resembled the one that had preceded the 8.4 earthquake, a series of gradually intensifying preshocks, sometimes coming in flurries. Then the big one.
Booker took four double-A batteries from two flashlights and wrapped them together with tape, attaching them to the capacitors. The batteries would charge the capacitors, which would send an electric current across a bridge wire connected to the detonator.
The timer looked like a digital alarm clock. Booker had carried it in one of his pockets. He wired the timer to an enabling plug on the exterior of the bomb’s hard case.
“It’s time to raise the critical question,” Booker asked. “Do we stick with the original plan and set it for four hours?”
“We might not have four hours,” Elizabeth said. “This fault seems primed to explode.” Like Atkins, she thought a major earthquake was imminent.
“I’d make it longer,” Murray said. “We don’t know what happened above us during that last shake, whether the passageways are still open. And we still need to lower the bomb into this hole. That’s going to take more time.”
“Then considering the differing opinions, I’d suggest we stick to the plan,” Booker said. He pushed two buttons on the timer. One set the hour and minute. The other set the trigger.
Atkins watched the red digits begin to flash on the small device, which tracked the seconds and minutes.
Four hours.
Earlier, it had seemed like plenty of time. It didn’t now.
He turned on the radio and got Steve Draper.
“We’ve started the countdown,” he said.
The radio crackled.
“Then get the hell out of there!”
It was the president’s voice.
Atkins explained they were going to lower the bomb into the crevasse to reach the two-thousand-foot maximum-effect level.
He briefly described what had happened to Walt Jacobs.
There was no answer. Then the radio clicked again. It was Draper.
“Did you feel that last shake?”
Atkins said, “I thought it was going to bury us.”
“It was a mag 5.1, John. Get out of there as fast as you can, pal.”
NEAR KALER, KENTUCKY
JANUARY 20
11:55 A.M.
BOOKER GENTLY SLID THE CAPACITORS AND batteries into a canvas bag, which he looped over the front of the bomb. He lashed it down with cord and tape. Then he and Murray tied a three-hundred-foot length of rope to both ends of the MK/B-61. They wrapped the rope several times around a steel post that had once supported the frame of the collapsed elevator shaft. Murray tied a white handkerchief at the two-hundred-foot mark.
With Booker operating the joysticks, Neutron lifted the bomb, then placed it over the side of the crevasse while Murray, Atkins, and the others held on to the rope, keeping it taut as they slowly lowered the weapon into position.
Atkins stood behind Wren and was surprised at his strength. A thick pack of shoulder muscles moved under his coveralls as he gripped the rope. The geologist was much stronger and fitter than he looked.
“Let it down a little more,” Booker said.
They lowered the bomb a few feet at a time until they reached the handkerchief. They looped the rope around the steel post and tied it down. The entire procedure had taken nearly half an hour.
Atkins went to the edge of the crevasse and took a final look at the bomb as it hung suspended against the rough wall of the trench. He could just make out the red glow of the timer, ticking off the seconds and minutes.
Would it go off on schedule?
Would it be a dud or a misfire?
Was it too powerful, or not powerful enough?
Booker put an arm around his shoulder. “Don’t think about it,” he said, guessing what was on Atkins’ mind. “We’ve done everything we could.”
“I hope so,” Atkins said. He knew you never did everything you could. There was always that small or large detail you forgot, the potential for a screw up.
Murray quickly got everyone back in line for the ascent. The sooner they were moving, the better he’d like it.
They picked up their canisters of dry foam and extra coils of rope. Murray told them to recheck the straps on their oxygen tanks.
“Unless we find out different, nothing’s changed,” he said. “We’re going back the same way we got down here, up the skip shaft to Level 15. Then up the main air shaft to the elevator cage on Level 8. Any questions?”
They started up the skip shaft. It was more difficult climbing up the steep incline than descending. What had taken nearly half an hour during the three-hundred-foot descent now ate up forty minutes of time. Tied together again, they had to lean into each step. Their leg muscles soon began to feel the strain and they had to stop once when Booker’s calves cramped up. Only Neutron had an easier time of it, carrying the large spool of non-1 fusing as it rolled up the shaft once used for the coal conveyor belt. Freed from the weight of the bomb, the robot moved effortlessly up the slope.
When they reached Level 15 Murray checked the temperature gauge. They stopped beside the three-foot-high red-painted number on the wall—15.
“Man, I don’t believe this,” he said. “It’s pushing ninety degrees. This ground’s a furnace.”
He didn’t have to tell that to Elizabeth or Atkins. Both were soaked through their heavy clothing. They all were.
They started down one of the dark, forty-foot-wide tunnels that had been carved out of the coal seam. They squeezed through a narrow space where part of the ceiling had collapsed and were approaching a crosscut that linked two of the tunnels when the ground heaved. They’d gone about four hundred feet.
The force of the tremor hurled Atkins down. He fell hard on his back, his air tank cracking against his spine. Elizabeth and Weston also fell. The ground kept moving, shaking back and forth like a vibrator. There was a deep rumble far below them, the sound of buried thunder.
“Get back! Move!” Murray was screaming at them as they scrambled to their feet.
